very rich startup ... F150 5.0L EFI
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From: sc montana
very rich startup ... F150 5.0L EFI
I've been having this problem since the last subzero temp period. When starting cold, I've had extremely rich conditions. Engine lopes bad when warming up. I replaced; Heated Oxygen Sensor, Fuel filter, spark plugs, air filter, IAC, MAP. I've cleaned the throttle body, cleaned and tested EGR, tested ECT, IAT, EVP.
I am still getting a rich lopeing condition at cold startup and it takes it much longer to warm than it used to. I got me a code reader and checked codes;
KOEO I got (11) system passed, In memory I got (33) EGR fault/ not closing (34) EVAP control fault, (41) No HEGO switching detected. next ran KOER test, results; (42) HEGO sensor voltage high/ system rich, (18) Spout circuit open - Spark Angle Word (SAW) failure.
All I can think is to test the HEGO, but my Chilton book says how to check, but tells me the voltage values are on a table that is not there! I also have a miniscule coolant leak that I can not locate.
anyone help this poorboy out?
I am still getting a rich lopeing condition at cold startup and it takes it much longer to warm than it used to. I got me a code reader and checked codes;
KOEO I got (11) system passed, In memory I got (33) EGR fault/ not closing (34) EVAP control fault, (41) No HEGO switching detected. next ran KOER test, results; (42) HEGO sensor voltage high/ system rich, (18) Spout circuit open - Spark Angle Word (SAW) failure.
All I can think is to test the HEGO, but my Chilton book says how to check, but tells me the voltage values are on a table that is not there! I also have a miniscule coolant leak that I can not locate.
anyone help this poorboy out?
Postmaster
Joined: Mar 2004
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From: Michigan
Well,I think you might want to look at that egr valve again.Your symptom sounds exactly like a partially open EGR,and that was what your code said.The EGR is supposed to stay completely closed until after warm up.
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From: sc montana
Yes, runs rich all the time ...... extremely rich at startup
It is running rich all the time, but excessively rich at startup for at least ten minutes. I cleared all the codes and drove it today, after about 2 warmups and 30 miles check engine light comes back on. Today it didn't want to return to idle, ran 1200rpm at stoplights. When I got home I let it run about 5 minutes then idle came down to 800rpm. Retested KOEO test gave code 11 (passed) memory had code 41, KOER test gave code 42, and code 18. I tried to get a cylinder balance test but could never get it to work. Tomorrow I will try my old HEGO ... maybe I got a bad one from NAPA. Was also questioning if my injecters are leaking gas into the manifold when parked. After I shut it down, i bled off the fuel rails. If this makes any differance on the cold start tomorrow, I will check fuel pressure.
I'm getting about 5mpg
yes the spout plug is in
I'm getting about 5mpg
yes the spout plug is in
Last edited by Skidly; Mar 5, 2005 at 12:18 AM.
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The cylinder balance test is not available on trucks, only cars. This is because the trucks are all batch fire designs, and the EEC can't turn off just one cylinder.
Pull the vacuum line off the fuel pressure regulator. Cycle the key off to on to off several times. Look for any sign of fuel at the fuel pressure regulator vacuum connection. If there is fuel there, the diaphragm has failed and this will cause rich running.
Code 18 may be caused by a broken resistor in the IDM circuit. The resistor is buried in the harness and is a little fragile, especially if you've been flexing the harness trying to find other problems. When this happens, there are no other real symptoms or consequences other than Code 18, so I would not work on this problem first.
Pull the vacuum line off the fuel pressure regulator. Cycle the key off to on to off several times. Look for any sign of fuel at the fuel pressure regulator vacuum connection. If there is fuel there, the diaphragm has failed and this will cause rich running.
Code 18 may be caused by a broken resistor in the IDM circuit. The resistor is buried in the harness and is a little fragile, especially if you've been flexing the harness trying to find other problems. When this happens, there are no other real symptoms or consequences other than Code 18, so I would not work on this problem first.
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From: sc montana
i've just tested my FPR, with engine idling my fuel pressure shows to be 80psi. What is the correct pressure? Can a modified air pressure guage give me an accurate enough reading here?
also when it was started cold during warm up I felt bottom of EGR valve and it did not get warm. During warmup, is the vacume to the valve supposed to be stronger (enough to hold the EGR open?) Is there a relay that controls this?
considering replacing FPR and a more thorough cleaning on the EGR as my next step
also when it was started cold during warm up I felt bottom of EGR valve and it did not get warm. During warmup, is the vacume to the valve supposed to be stronger (enough to hold the EGR open?) Is there a relay that controls this?
considering replacing FPR and a more thorough cleaning on the EGR as my next step
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Your fuel pressure is way, way too high. It may be the regulator, or it may be that the fuel return line is blocked. The pressure should be 39 PSI KOEO, dropping to about 32 PSI at idle. The regulator is relatively inexpensive. The probability is fairly high that it is the problem. The air pressure guage isn't the greatest, but should be good enough to tell the difference between 80 PSI and something more reasonable.
The EGR valve should remain closed until the engine is thoroughly warmed up, AND operating faster than at idle. The computer controls it, using the EVR to control the amount of vacuum going to the diaphragm. There should be no vacuum to the EGR during warm up or at idle -- a spring holds it closed.
The EGR valve should remain closed until the engine is thoroughly warmed up, AND operating faster than at idle. The computer controls it, using the EVR to control the amount of vacuum going to the diaphragm. There should be no vacuum to the EGR during warm up or at idle -- a spring holds it closed.
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From: sc montana
tested again
Reinstalled old HEGO and retested
KOEO = passed (11)
CM= 34
KOER = 42, 18, 33,
Engine idle Fuel pressure 85psi, all rpms = 85psi
remove vacum line to FPR ... 85psi
reconnect vacum line to FPR .... 85psi
time for a new FPR?
KOEO = passed (11)
CM= 34
KOER = 42, 18, 33,
Engine idle Fuel pressure 85psi, all rpms = 85psi
remove vacum line to FPR ... 85psi
reconnect vacum line to FPR .... 85psi
time for a new FPR?
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If you promise to be careful, there is a way to determine whether the fuel pressure issue is the fault of the regulator or the return line/shuttle valve.
Bleed off the fuel pressure. Disconnect the return line from the regulator. Route a rubber hose from the regulator return port over to an empty gas can. Use the gas can to recieve the discharge from the regulator. Cycle the key from off to on to off to on. If the pressure still goes up to 50+ PSI, the regulator is bad. If it stays at 39 or so, the return line is blocked.
Alternatively, just change out the regulator. They aren't very expensive.
Bleed off the fuel pressure. Disconnect the return line from the regulator. Route a rubber hose from the regulator return port over to an empty gas can. Use the gas can to recieve the discharge from the regulator. Cycle the key from off to on to off to on. If the pressure still goes up to 50+ PSI, the regulator is bad. If it stays at 39 or so, the return line is blocked.
Alternatively, just change out the regulator. They aren't very expensive.
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Just curious what the FPR cost you. I'm in Hawaii and they're running about $60 here. I keep reading people say that they're not expensive. One guy even made a comment that it cost him $20 and an afternoon to change it.
Thanks,
Jon
Thanks,
Jon
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